• Wind and Structures
• /
• v.1 no.3
• /
• pp.243-253
• /
• 1998

The paper deals with numerical analysis of interference galloping of two elastically supported circular cylinders of equal diameters. The basis of the analysis is quasi-steady model of this phenomenon. The model assumes that both cylinders participate in process of interference galloping and they have two degrees of freedom. The movement of the cylinders is written as a set of four nonlinear differential equations. On the basis of numerical solutions of this equations the authors evaluate the correctness of this quasi-steady model. Then they estimate the dependence of a critical reduced velocity on the Scruton number, turbulence intensity and arrangements of the cylinders.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.12A
• /
• pp.1014-1022
• /
• 2009

In this paper, interference analysis is carried out to obtain the operating criterion and coexistence condition between digital television devices and cognitive radio-based mobile wimax devices in the UHF (Ultra High Frequency) broadcasting frequency bands. To this end, an efficient interfering calculation tool known as SEAMCAT (Spectrum Engineering Advanced Monte-Carlo Analysis Tool) is employed to acquire the coexistence criterions between heterogeneous radio links operating in the same portion of spectrum. As a result, these criterions will be used to achieve interference temperature limit level applied to interference temperature model for analyzing the capacity of cognitive radio receivers accurately.

• ETRI Journal
• /
• v.37 no.3
• /
• pp.439-449
• /
• 2015

Human body communication (HBC) is being recognized as a new communication technology for mobile and wearable devices in a body area network (BAN). This paper presents co-channel interference experienced by HBC supporting the physical layer in the IEEE 802.15.6 BAN standard. To analyze the co-channel interference, a co-channel interference model is introduced, and space-domain and time-domain parameters representing an interference environment are generated using the co-channel interference model. A new signal-to-interference ratio (SIR) parameter depending on the peak amplitudes of the data signals causing co-channel interference is defined; co-channel interference can be easily analyzed and modelled using the newly defined SIR. The BER degradation model derived using the co-channel interference model and SIR in this paper can be effectively used to estimate the performance.

• Journal of Advanced Navigation Technology
• /
• v.6 no.4
• /
• pp.318-325
• /
• 2002

In this paper, the effects of the interference environments on the performance of the time hopping(TH) binary PPM impulse radio(IR) system are presented. Based on the monocycle pulse available within the frequency of 3.1~10.6 GHz permitted for application by FCC, a PPM-modulated TH IR system simulator was designed and followed by the analysis of the monocycle pulse characteristics as well as the system performance. Particularly for the evaluation of the system performance, the multiple access interference and the narrowband system interference signals were considered as the interference signals. Since the narrowband system interference signal has very narrow bandwidth and very large amplitude compared with those of IR system, the analysis of the IR system performance was implemented by considering the interference power and band fraction ratio of the narrowband interference signal.

• Cement Symposium
• /
• no.1
• /
• pp.69-91
• /
• 1973

To obtain a more accurate results in alkali analysis of cement and its raw materials we must solve some difficult problems. The most important problem is not only dissoloing the sample with keep up alkali content but compensating interference effects. Her

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.6A
• /
• pp.588-599
• /
• 2007

This paper presents the coexistence issues between M-WiMAX TDD and WCDMA FDD systems. To improve the M-WiMAX system performance and to reduce the adjacent channel interference to WCDMA FDD system, transmit and receive beamforming techniques are applied in the base stations of M-WiMAX system. Furthermore, we propose an adjacent channel interference modeling methodology, which captures the effect of transmit beamforming on the adjacent channel interference. Besides, we verify the performance improvement in the uplink of WCDMA system due to the transmit beamforming in M-WiMAX downlink based on the proposed adjacent channel interference modeling methodology. We also verify the performance enhancement due to the receive beamforming in the uplink of M-WiMAX system through system level Monte Carlo simulations, considering random user position, the effect of shadowing and multi-path fading channel. Discussions on the gain of applying transmit and receive beamforming in M-WiMAX system comparing the case of SISO system are also included. Furthermore, we present the performance of cosited M-WiMAX and WCDMA systems, considering commercial deployment, additional channel filter at base stations and the effects of TxBF and RxBF.

• International Journal of Control, Automation, and Systems
• /
• v.6 no.6
• /
• pp.884-893
• /
• 2008

This paper analyzes, through simulations, GNSS interference mitigation performance against wideband and narrowband interferences by using spatial-temporal adaptive processing(STAP). The mathematical analysis results demonstrate that the array configuration has a considerable effect on the spatial-temporal correlation function. Based on the results, different array configurations are presented to evaluate and observe the effect on interference mitigation. The analysis results are further assessed through simulations.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.1
• /
• pp.40-47
• /
• 2013

By virtue of Rec. ITU-R P.1546 and geography information system, interference analysis for the fixed wireless system and radar has been presented based upon the frequency-distance rules with minimum coupling loss, and a comprehensive methodology for assessing interoperability between systems was examined in terms of received signal, protection ratio, frequency dependent rejection. Also to find the antenna gain from a discrimination angle, a useful S-I plane was introduced based on signal and interference vectors derived from the real map with geographic information. To show some computational results, geography information on the map was taken for the given area, and field strength and path profile were illustrated for the radar and fixed wireless system operating at 2.7 GHz, for convenience. In addition the interference effect of receiver was also checked as a function of radar beam direction including protection ratio and frequency dependent rejection. The developed interference analysis can be actually applied to evaluate interoperability for wireless systems in the VHF and UHF bands.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.5
• /
• pp.348-357
• /
• 2005

We have tried to analyze the SEMG interference pattern quantitatively and automatically using T/A variables ZC, TN, mSA, mSD, UCA, AIPEA, ACT and NSS. For the analysis, we have carried out experiments on 14 SEMG interference patterns recorded from the biceps brachii, first dorsal interosseus and abductor policis brevis muscles. Emphasis was placed on the following 3 points in the experiments. 1) Suitable amplitude threshold for the automatic detection of the T/A variables. 2) Variation of the T/A variables to varying $\%$MVC. 3) Variation of the T/A variables to the sustained contraction for 30 seconds. Results of the experiments showed that T/A analysis of the SEMG interference Pattern can be effective tools for diagnostic purposes instead of the conventional NEMG method.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.09a
• /
• pp.184-187
• /
• 2001

This study presents procedure and analysis method for not well known slug interference tests. Results of the slug interference tests were compared with those of pumping and recovery tests and conventional slug tests.